Did you ever wonder what those strange conglomerations of letters meant? Here's your chance to find out what those NASA acronyms stand for. About Space and Astronomy presents the Guide to NASA Acronyms. From Uranium to Urine Collection Transfer Assembly and United States of America to Unmanned Vertical Flight, you'll find them here. This page lists acronyms starting with U. For others, click on the appropriate letter above or below.

[U]

U: Uranium
U-SB: Unified S-Band
U/C: Under Current
U/D: Update
U/L: Uplink (UPLK preferred)
U/M: Unit of Measure
U/M: Unmanned
U/M: Unscheduled Maintenance
U/O: Used on
U/V: Under Voltage
U/W: Used with
UA: Microampere
UB: Upper Brace
UB: UpUtility Bridge
UBE: Universal Bus Exercisor
UBIC: Universal Bus Interface Controller
UCD: Urine Collection Device
UCN: Uniform Control Number
UCPU: Urine Collection and Pretreatment Unit
UCR: Unsatisfactory Condition Report
UCTA: Urine Collection Transfer Assembly
UD: Update
UDB: Update Buffer
UDF: Utility and Data Flow
UDL: Updata Link
UDL: Update Link
UDMH: Unsymmetrical Dimethylhydrazine
UDMH/H: Unsymmetrical Dimethylhydrazine Hydrazine Blend
UDOP: Ultrahigh Doppler
UDS: Universal Documentation System
UER: Unique Equipment Register
UF: Microfarad
UFD: User File Directory
UG: Microgram
UHF: Ultrahigh Frequency
UHF: Ultrahigh frequency
UL: Upper Limit
UL: Underload
UL: Uplink
UL: Upper Left (S-Band Antenna)
ULA: "Fairbanks, Alaska (STDN Site)"
ULL: Ullage
ULO: Unmanned Launch Operations
ULT: Ultimate
UMB: Umbilical
UMBC: Umbilical Cord Cable
UMVF: Unmanned Vertical Flight
UNBAL: Unbalance
UNDK: Undock
UNDV: Undervoltage
UNIV: Universal
UNLCH: Unlatch
UNLK: Unlock
UP: Upper
UPLK: Uplink
UPP: User Parameter Processing
UPS: Uninterruptible Power Supply
UPS: Uninterruptible Power System
UPS: Upright Perigee Stage
UPTLM: UPlink Telemetry
UR: Unsatisfactory Report
UR: Upper Right
URA: Urine Receptacle Assembly
URN: Urine
URT: Upright
USA: United States of America
USAF: United States Air Force
USB: Upper Side Band
USB: Unified S-Band
USBE: Unified S-Band Equipment
USBI: "United Space Booster, Inc."
USBS: Unified S-Band System (Subsystem)
USEC: Microsecond
USN: United States Navy
USNS: United States Navy Ship
USRA: Universities Space Research Association
UST: Universal Servicing Tool
UST: United States Testing (Company)
UT: Unit Tester
UT: Universal Time
UT: Umbilical Tower
UT&GS: Uplink Text and Graphics System
UTC: Unit Test Cases
UTC: United Technology Center
UTC: Universal Test Console
UTC: Coordinated Universal Time
UTE: Universal Test Equipment
UTI L: Utility
UTLM: Up Telemetry
UTS: Urine Transfer System
UUT: Unit Under Test
UVD: Under Voltage Device
UVF: Unmanned Vertical Flight
Ul: User Interface
Ul: Unit of Issue

For more NASA acronyms, select a letter below or at the top of the page to continue with the About Astronomy and Space Guide to NASA Acronyms.